code: def pytest_collection_modifyitems(config, items):
      # Setting this to True here allows tests to be set up before dispatching
      # any function call to a backend.
      networkx.utils.backends._dispatchable._is_testing = True
      if (
          automatic_backends := networkx.utils.backends._dispatchable._automatic_backends
      ):
          # Allow pluggable backends to add markers to tests (such as skip or xfail)
          # when running in auto-conversion test mode
          backend = networkx.utils.backends.backends[
              automatic_backends[0]
          ].load()
          if hasattr(backend, "on_start_tests"):
              getattr(backend, "on_start_tests")(items)
  
      if config.getoption("--runslow"):
          # --runslow given in cli: do not skip slow tests
          return
      skip_slow = pytest.mark.skip(
          reason="need --runslow option to run"
      )
      for item in items:
          if "slow" in item.keywords:
              item.add_marker(skip_slow)
  
file_path: networkx/networkx/conftest.py
imports: import os
  import sys
  import warnings
  from importlib.metadata import entry_points
  import pytest
  import networkx
label_desc: Use image node_id 3 for calling a global function with example usage: pytest_collection_modifyitems(config, items) without return types